Wireless communication systems have taken a step to support higher transfer ratio to meet increasing wireless data traffic demand.
Among them, the fourth generation (4G) communication system has been evolved mainly for improvement of spectral efficiency based on communication technologies like Orthogonal Frequency Divisional Multiple Access (OFDMA), Multiple Input Multiple Output (MIMO), etc., in order to increase the data transfer ratio. However, only the improvement of spectral efficiency may hardly meet the soaring wireless data traffic demand.
Today's increasing demand of smartphones and tablets and increase in associated applications in need of greater data traffic are fueling the data traffic demand. A way of addressing the increase in data traffic is to use ultra wideband frequencies in the ultrahigh-frequency domain.
In case of wireless communication in the ultrahigh-frequency band, by nature of frequency characteristics, propagation loss, such as path loss, shadow fading, reflection loss, or the like may increase. This may shorten the (effective) distance of arrival of ultrahigh-frequencies, causing significant decrease in coverage of wireless communication services in the ultrahigh-frequency domain.
On the other hand, since the ultrahigh-frequency has a very short wavelength, it is easy to apply beamforming with multiple small antennas. Accordingly, mitigation of the propagation path loss with the beamforming technology may increase the propagation distance of radio waves and thus possibly expand service areas.
Beamforming based systems may apply the beamforming technique not only to the data channel but also to the control channel, i.e., beamforming may be applied and operated for Synchronization Signals (SSs) for obtaining synchronization of downlink (DL) or Random Access Channels (RACHs) of uplink (UL).